U.S. patent application number 11/569018 was filed with the patent office on 2008-01-24 for spray-regulating system incorporated in aircraft anti-icers.
Invention is credited to Elo Svanebjerg.
Application Number | 20080017756 11/569018 |
Document ID | / |
Family ID | 34957448 |
Filed Date | 2008-01-24 |
United States Patent
Application |
20080017756 |
Kind Code |
A1 |
Svanebjerg; Elo |
January 24, 2008 |
Spray-Regulating System Incorporated in Aircraft Anti-Icers
Abstract
The invention relates to de-icing and anti-icing procedures
performed on airplanes on the ground, wherein a fluid is sprayed
from the boom or arm of a de-icer installation onto the aircraft. A
spray-regulating system is incorporated in aircraft anti-icers
comprising a tank (1) with anti-icing fluid, a fluid pump (2) with
a drive motor (6), and a hose or pipeline (7) between the pump (2)
and a spray nozzle (3) located on an elevating boom, arm or
operator's platform so that the fluid can be pumped from the tank
(1) to the spray nozzle (3), said system further comprising a
central control unit (5), a pressure-signal-generating pressure
sensor (4) located proximate to the inlet of nozzle (3), and a
regulating device (8) for the motor (6) to adjust the motor
momentum, wherein a constant pressure upstream of the nozzle (3)
and consequently over said nozzle (3) is maintained by said control
unit (5) producing a signal calculated on a pressure signal
received from the sensor (4) and the pressure required upstream of
the nozzle (3), and said signal being transmitted to the regulating
device (8), which then adjusts the momentum of the pump motor (6)
and thereby adjusts the flow rate and or pressure rate in the
pipeline (7).
Inventors: |
Svanebjerg; Elo;
(Tappernoje, DK) |
Correspondence
Address: |
STITES & HARBISON PLLC
1199 NORTH FAIRFAX STREET
SUITE 900
ALEXANDRIA
VA
22314
US
|
Family ID: |
34957448 |
Appl. No.: |
11/569018 |
Filed: |
May 12, 2004 |
PCT Filed: |
May 12, 2004 |
PCT NO: |
PCT/IB04/50657 |
371 Date: |
November 13, 2006 |
Current U.S.
Class: |
244/134A |
Current CPC
Class: |
B64F 5/20 20170101; B05B
12/085 20130101; B64F 5/23 20170101 |
Class at
Publication: |
244/134.00A |
International
Class: |
B64D 15/02 20060101
B64D015/02 |
Claims
1. Spray-regulating system incorporated in aircraft anti-icers
comprising a tank with anti-icing fluid, a fluid pump with a drive
motor, and a hose or pipeline between the pump and a spray nozzle
located on an elevating boom, arm or operator's platform so that
the fluid can be pumped from the tank to the spray nozzle, further
comprising a central control unit, a pressure-signal-generating
pressure sensor and a regulating device for the motor to adjust the
motor momentum, said control unit producing a signal calculated on
a pressure signal received from the sensor and the pressure
required upstream of the nozzle, and said signal being transmitted
to the regulating device, characterized in the sensor being mounted
in close proximity to the spray nozzle whereby the regulating
device adjusts the momentum of the pump motor and thereby adjusts
the flow rate and or pressure rate in the pipeline to secure a
constant pressure in close proximity to i.e. substantially directly
at, the nozzle irrespective of differences in height of the nozzle
relative to the pump.
2. Spray-regulating system according to claim 1, characterized in
the central control unit being comprised of a signal receiver and a
signal transmitter and a computer to continuously calculate the
proper motor-regulating signal based on the input from the pressure
sensor.
3. Spray-regulating system according to claim 1, characterized in
further comprising a tank for water, and means for mixing the
anti-icing fluid and water before it is pumped into the pipeline by
means of the momentum-regulated drive motor driving one or more
pumps for delivery of fluid into the pipeline.
4. Spray-regulating system according to claim 1, characterized in
comprising further sensors to measure further parameters, e.g. the
viscosity of the fluid based on mixture ratio and temperature,
wherein said further parameters are processed by the control unit
together with the pressure signal, and the resulting signal is sent
to the regulating device.
5. Anti-icer comprising a vehicle and an elevating boom, arm or
platform with a spray-regulating system according to claim 1.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to de-icing and anti-icing
procedures performed on airplanes on the ground, wherein a fluid is
sprayed from the boom or arm of a de-icer installation onto the
aircraft in order to remove or prevent frozen contaminations on the
surface. Hereafter the expression de-icing means to remove snow and
ice from the aircraft surface, the de-icing being performed by
applying a heated low-viscosity fluid. The expression anti-icing is
a treatment normally performed after de-icing; the fluid used for
anti-icing is a thickened fluid with a higher viscosity. The
purpose of the thickened anti-icing fluid is to adhere to the
aircraft surface until the aircraft is airborne, to protect the
aircraft against precipitation freezing on the surface.
BACKGROUND OF THE INVENTION
[0002] Such de-icing/anti-icing equipment is widely known from e.g.
the patent literature and also from U.S. Pat. No. 4,565,321
"Vehicle for de-icing aircraft" belonging to the assignee of the
present application.
[0003] The basic layout of the equipment comprises e.g. a vehicle
frame or truck and a lever or boom extending from the vehicle and
carrying an operator's platform from where the spraying onto an
aircraft is provided.
[0004] In this technical field it is known to regulate the flow of
liquid by regulating the pump motor and EP 0 876 842 B1 "Mixing
apparatus for spraying a liquid mixture" also in the name of the
present assignee describes the use of two tanks containing liquids
to be mixed before spraying, wherein a motor-regulating system is
provided for maintaining a required mixing ratio.
[0005] In general, such equipment will comprise a number of
spraying components including tanks with de-icing and anti-icing
fluid, fluid pumps with drive motors, and hoses or pipelines
between the pumps and the spray nozzle to pump the fluid from the
tank to the spray nozzle at the platform.
[0006] In prior art equipment it is common standard to maintain a
constant flow rate when anti-icing fluid is sprayed, in order to
achieve a constant pressure drop from the fluid pump to the fully
opened nozzle, However, this results in too much fluid being used,
because the flow from the nozzle cannot be adjusted according to
the actual needs.
[0007] For anti-icing purposes the fluid will have added thickeners
in order to hold a certain fluid-layer thickness on the aircraft
surface for an extended period (holdover time) after application.
The resulting increased viscosity makes the fluid sensitive to
shearing damages, when higher pressure drops over the nozzle occur
because the fluid will be accelerated very much and the molecular
structure would be stretched beyond cohesion limits.
[0008] The occurrence of lower pressure drops over the nozzle would
mean too short spray distance of the fluid jet to obtain a
satisfactory distribution of fluid on the surface of the
aircraft.
SUMMARY OF THE INVENTION
[0009] As opposed to the constant flow scenario the inventor has
pursued establishing a constant pressure drop over the nozzle even
if the flow rate through the pipeline is variable. Thereby it is
possible to progressively match the pump pressure required to
compensate for the differences in height of the nozzle relative to
the pump and for the pressure drop derived from the variable flow
in the pipeline.
[0010] According to the invention a pressure-regulating system is
provided, which secures a constant pressure upstream of the nozzle
and thereby a constant pressure drop over the spray nozzle
irrespective of the height of the operator's platform relative to
the pump, and of the pressure drop in the pipeline.
[0011] The pressure-regulating system comprises a pressure sensor
mounted in close proximity to the nozzle and transmitting its
measured data to a central control unit, which further instructs a
regulator device to adjust the momentum of the fluid pump drive
motor and thereby varying the flow rate and for pressure rate in
the pipeline.
[0012] According to the invention it is possible to maintain a
constant pressure on the upstream side of the nozzle and thereby a
constant pressure drop over the nozzle with a variable fluid flow
through the nozzle. The constant pressure will optimize the spray
pattern without damaging the fluid. With a variable flow it is
possible to adjust the amount of fluid sprayed to the amount needed
for covering the surface of the aircraft.
[0013] According to a further embodiment of the invention the
central control unit comprises a signal receiver and a signal
transmitter and a computer to continuously calculate the proper
motor-regulating signal based on the input data from the pressure
sensor.
[0014] Moreover, the spray-regulating system according to the
invention is further comprising a tank for water, and means for
mixing the anti-icing fluid and water before it is pumped into the
pipeline by means of the momentum-regulated drive motor driving one
or more pumps for delivery of fluid into the pipeline.
[0015] Yet another embodiment of the invention comprises further
sensors to measure parameters, e.g. the viscosity of the fluid
based on mixture ratio and temperature, wherein such further
parameter data are processed by the control unit together with the
pressure signal, and the resulting signal is sent to the regulating
device
[0016] The spray-regulating system according to the invention can
also be used for spraying equipment comprising several tanks and
pumps working in parallel.
[0017] Finally, there is provided an anti-icer comprising a vehicle
and an elevating boom, arm or platform with a spray-regulating
system according to the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a diagram showing the spray-regulating system of
the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Referring to FIG. 1 a spray-regulating system according to
the invention is illustrated. The system comprises a tank 1
containing anti-icing fluid and being connected to a
fluid-diaphragm pump 2 driven by a motor 6. From said pump 2
anti-icing fluid is pumped through a hose or pipeline 7 to the
spray nozzle 3 so that it is sprayed onto the surfaces of an
aircraft and protects them from building up frozen contaminations
on the surface.
[0020] In close proximity to the inlet of the spray nozzle 3, a
pressure sensor 4 is mounted in such a way that the inlet pressure
is measured and reported to a central control unit 5. Said control
unit 5 receives the pressure signal from the sensor 4 and based on
the possible difference between the actual pressure and the
required pressure a signal is produced and transmitted to a
regulating device 8, which will then adjust the speed of the pump
motor 6 and thereby influence the fluid flow rate in the pipeline
7.
[0021] In this way it is possible to adjust for pressure drops in
the hose or pipeline 7 when the flow rate is variable and for the
pressure loss in accordance with the height of the spray nozzle
relative to the height of the pump, which ensures a constant
pressure upstream of the nozzle and thereby a constant pressure
drop over the nozzle, so that the spray pattern is optimized
without damage to the thickened anti-icing fluid.
[0022] Obviously, the control parameters being used to calculate
the signal transmitted by the central control unit 5 can take into
account measures of not only the pressure but also the viscosity of
the fluid in dependence on the mixture ratio and temperature.
* * * * *